A bug was found in the way Thunderbird handled anonymous functions during regular expression string replacement. It is possible for a malicious HTML mail to capture a random block of client memory. The Common Vulnerabilities and Exposures project has assigned this bug the name CAN-2005-0989.

A bug was found in the way Thunderbird validated several XPInstall related JavaScript objects. A malicious HTML mail could pass other objects to the XPInstall objects, resulting in the JavaScript interpreter jumping to arbitrary locations in memory. (CAN-2005-1159)

A bug was found in the way the Thunderbird privileged UI code handled DOM nodes from the content window. An HTML message could install malicious JavaScript code or steal data when a user performs commonplace actions such as clicking a link or opening the context menu. (CAN-2005-1160)

A bug was found in the way Thunderbird executed JavaScript code. JavaScript executed from HTML mail should run with a restricted access level, preventing dangerous actions. It is possible that a malicious HTML mail could execute JavaScript code with elevated privileges, allowing access to protected data and functions. (CAN-2005-1532)

A bug was found in the way Thunderbird executed Javascript in XBL controls. It is possible for a malicious HTML mail to leverage this vulnerability to execute other JavaScript based attacks even when JavaScript is disabled. (CAN-2005-2261)

A bug was found in the way Thunderbird handled certain Javascript functions. It is possible for a malicious HTML mail to crash the client by executing malformed Javascript code. (CAN-2005-2265)

A bug was found in the way Thunderbird handled child frames. It is possible for a malicious framed HTML mail to steal sensitive information from its parent frame. (CAN-2005-2266)

A bug was found in the way Thunderbird handled DOM node names. It is possible for a malicious HTML mail to overwrite a DOM node name, allowing certain privileged chrome actions to execute the malicious JavaScript. (CAN-2005-2269)

A bug was found in the way Thunderbird cloned base objects. It is possible for HTML content to navigate up the prototype chain to gain access to privileged chrome objects. (CAN-2005-2270)

Users of Thunderbird are advised to upgrade to this updated package that contains Thunderbird version 1.0.6 and is not vulnerable to these issues.

4. Solution:

Before applying this update, make sure all previously released errata relevant to your system have been applied.

This update is available via Red Hat Network. To use Red Hat Network, launch the Red Hat Update Agent with the following command:

up2date

This will start an interactive process that will result in the appropriate RPMs being upgraded on your system.